// Invariant: all elements at indices in [knownRunStart, knownRunEnd) are nonnull.
      // If knownRunStart == knownRunEnd, this is vacuously true.
      // When knownRunEnd exceeds hashTable.length, it "wraps", detecting runs around the end
      // of the table.
      int knownRunStart = 0;
      int knownRunEnd = 0;

      outerLoop:
      while (knownRunStart < hashTable.length) {